The Chinook wind is called the Föhn effect in Europe. That's what makes Alberta warmer than the more easterly continental provinces.
Although the Föhn effect caused by the Scandinavian mountains is somewhat attenuated when it reaches Finland, it may still cause notable warm spells in the western and the northwestern parts of the country in particular.
Moosonee is at the southern tip of James Bay, which is a southern extension of Hudson Bay.
There could be a winter road to Moosonee from the south. Google Maps shows a road between Moosonee and some more northerly localities along the shore.
I've watched Ice Road Truckers. It's a fascinating show. Those people have to deal with some pretty extreme conditions.
Trying to drive up there would be ill-advised indeed. You could bring enough fuel with you but your car could break down or the road might be impassable or too dangerous to drive on.